Constructive topics of interest related to aviation that do not match the other section descriptions below (as long as it is somewhat related to aviation, flying, learning to fly, sport pilot, light sport aircraft, etc.). Please, advertisements for Viagra will be promptly deleted!"

My local mechanic, Bill, works on a variety of aircraft including vintage jet aircraft. He recently finished restoring an L-29 that the owner recently sold. The owner hired a ferry pilot (ATP for a major airline) to take the L-29 from Dallas to California. The plane had sat for awhile so Bill went to check everything out and all was well. The pilot was delayed by a day (his personal parachute didn't have the right inspections stickers to be checked as luggage) so he was somewhat in a hurry to get going. Bill suggested they put the plane up on blocks and check the hydraulics as he has found air bubbles can develop in the L-29 system when it sets for awhile. Working the gear, flaps and air brakes can work these out. You then need to top off the fluid, which can be significant. The pilot has no time in an L-29 but does have time in an L-39.

The ferry pilot first could not get the L-29 started. Bill thought that was odd since he had no trouble a day earlier. After watching the ferry pilot's process, Bill noticed he was engaging the air starter and not the ground starter. Engaging the correct switch and the plane started easily. The pilot worked the flaps and air brake thoroughly. Bill suggested he turn off the plane for him to top off the fluid but the pilot declined and took off for a test flight. Bill remarked that pilot put the plane through some impressive maneuvers and was clearly a gifted pilot. He landed without incident and taxied back to the hangar. Bill offered again to check and top off the hydraulic fluid but the pilot declined. He grabbed his bag and was off.

It really looks sleek sitting there without the gear. Kind of like my model airplanes on the shelf when I was a kid

I just cannot imagine a test hope NOT followed by a very close inspection.

The comment

...no leaks detected

doesn't add up. You mentioned air bubbles but bubbles form when there are losses. There are few other reasons for them to form but hydraulic fluid is not a carbonated beverage so there are leaks somewhere in the system.